Thin films are deposited onto substrates for a variety of applications. For example, thin films are used in electronic and optical devices. The thin film may be single-layered structure or a multi-layered structure, and material of the thin film may be metal, semiconductor, or insulator. In the deposition processes, evaporation is a common method of thin-film deposition.
Evaporation device includes a chamber, a crucible and a carrier positioned in the chamber, in which the crucible is employed to contain evaporation materials. The carrier is employed to support workpieces and keep the workpieces toward the crucible. The evaporation material is placed in the crucible that is inserted into the chamber, and the electron beams are directed into the crucible. However, during the heating process, it is difficult to monitor the status of the evaporation material, and therefore, the yield rate of the evaporation process is difficult to be controlled as well.